3.3 kV Back-Gate-Controlled IGBT (BC-IGBT) Using Manufacturable Double-Side Process Technology

Full integration of a back-gate-controlled IGBT (BC-IGBT), which comprises top and bottom independently controlled MOS gates, is experimentally demonstrated. By using the back side MOS gate for accelerating electron drain and blocking of hole injection, more than 60% reduction of turn-off loss was achieved. Instead of the conventional wafer bonding approach, a cost effective process flow using double side lithography has been developed and used. Thanks to the process flexibility, back side design was carefully optimized to achieve stable operation and manufacturability, in addition to low switching loss. BC-IGBT will provide a new technological option for expanding the applicable switching frequency / voltage range of Si power devices.